I love Commander.

My main Commander decks currently use:
Kaalia of the Vast
Vorel of the Hull Clade
Rafiq of the Many
Oloro, Ageless Ascetic
Captain Sissay
Mayael, the Anima
Sliver Overlord

And I'm working on building:
Marchessa, the Black Rose
Trostani, Selesnyia's Voice (may replace Commander with Rhys, the Redeemed if I can get one)
Skullbriar, the Walking Grave
Jhoira of the Ghitu (though I have basically nothing I need for it :x)

... Yeah, I have too many decks. But I like them all! Also, my favorite guild of Ravnica has always and will always be Simic.